Birt-Hogg-Dube Syndrome
A rare inherited condition affecting the skin, lungs, and kidneys
Quick Facts
- Type: Inherited genetic disorder
- Gene involved: FLCN (folliculin)
- Main concerns: Lung cysts, collapsed lung, kidney tumors
- Inheritance: Autosomal dominant
Overview
Birt-Hogg-Dube (BHD) syndrome is a rare inherited condition caused by a change (mutation) in a gene called FLCN, which produces a protein known as folliculin. The syndrome was named after the three physicians who first described it. It mainly affects three parts of the body: the skin, the lungs, and the kidneys.
People with BHD often develop small, harmless skin bumps on the face and upper body, cysts in the lungs that can lead to a collapsed lung, and an increased lifetime risk of developing kidney tumors. Because BHD is passed down in families, a single affected parent has a 50 percent chance of passing the gene change to each child. With awareness and regular monitoring, the most serious complications can usually be detected early and managed effectively.
Symptoms
Signs of BHD syndrome often appear in adulthood and can vary widely, even within the same family. The most recognizable features include:
- Skin bumps: Small, dome-shaped, flesh-colored or whitish papules (called fibrofolliculomas) typically appearing on the face, neck, and upper chest from the third decade of life onward.
- Lung cysts: Thin-walled air-filled spaces in the lungs, usually causing no symptoms unless one ruptures.
- Collapsed lung (pneumothorax): Sudden chest pain and shortness of breath if a lung cyst bursts and air leaks into the chest cavity.
- Kidney tumors: Often silent in early stages; sometimes found through screening before causing symptoms.
A sudden collapsed lung, with sharp chest pain and breathlessness, needs urgent medical evaluation.
Causes
BHD syndrome is caused by an inherited change in the FLCN gene. This gene normally helps control cell growth and acts as a tumor suppressor. When it does not work properly, cells in the skin, lungs, and kidneys are more prone to forming growths and cysts.
The condition is inherited in an autosomal dominant pattern, meaning only one altered copy of the gene is enough to cause the syndrome. In most cases the gene change is passed from a parent, though occasionally it arises new in a person with no family history.
Risk Factors
- Having a parent, sibling, or child diagnosed with BHD syndrome
- A family history of unexplained collapsed lungs, kidney tumors, or characteristic facial skin bumps
- A known FLCN gene change identified through genetic testing
BHD is rare, and there is nothing a person can do to acquire it during life; the underlying gene change is present from birth.
Diagnosis
BHD is suspected when a person has the typical combination of skin, lung, and kidney findings or a relevant family history. Doctors may use:
- Skin examination and biopsy: To confirm that bumps are fibrofolliculomas.
- Chest imaging (CT scan): To detect lung cysts.
- Kidney imaging: Ultrasound, CT, or MRI to look for tumors.
- Genetic testing: A blood test to identify a change in the FLCN gene, which confirms the diagnosis and helps guide screening for relatives.
Treatment
There is no cure for the underlying gene change, so care focuses on monitoring and treating each affected area:
- Skin bumps: Usually harmless and treated only for cosmetic reasons using laser therapy or other dermatologic procedures, though they may return.
- Collapsed lung: Managed by removing trapped air; recurrent episodes may need a procedure to help the lung stay sealed against the chest wall.
- Kidney tumors: Followed with regular imaging; when treatment is needed, surgeons aim to remove tumors while preserving as much healthy kidney as possible.
Lifelong kidney surveillance is the cornerstone of care because early detection allows tumors to be treated before they spread.
Prevention
BHD cannot be prevented because it is inherited, but its complications can be managed proactively:
- Regular kidney imaging on a schedule recommended by your doctor
- Not smoking, which lowers the risk of lung problems and collapsed lung
- Being cautious with activities involving large pressure changes, such as scuba diving, after discussing risks with your doctor
- Genetic counseling for family members to decide whether testing is right for them
When to See a Doctor
Speak with a doctor if you have several characteristic skin bumps, a personal or family history of collapsed lung, or relatives with BHD or unexplained kidney tumors. Seek emergency care right away if you develop:
- Sudden, sharp chest pain
- Sudden shortness of breath
- Blood in the urine or a new lump or pain in the side or back
Frequently Asked Questions
Is Birt-Hogg-Dube syndrome a form of cancer?
BHD itself is not cancer, but it increases the lifetime risk of developing kidney tumors, some of which can be cancerous. The skin bumps and lung cysts are benign. Regular kidney screening allows tumors to be found and treated early.
How is Birt-Hogg-Dube syndrome inherited?
BHD follows an autosomal dominant pattern, so a person with one altered FLCN gene has a 50 percent chance of passing it to each child. It usually comes from an affected parent, though it can occasionally arise new. Genetic counseling helps families understand their risk.
Why do people with BHD get collapsed lungs?
BHD causes thin-walled cysts to form in the lungs, and these can rupture and let air escape into the chest, causing a lung to collapse. This typically brings sudden chest pain and breathlessness and needs prompt medical care. Avoiding smoking can lower the risk.
Can the skin bumps of BHD be removed?
The skin bumps are harmless and treated only for cosmetic reasons, often with laser or other dermatologic procedures. They tend to recur over time, so treatment may need to be repeated. They do not turn into skin cancer.
What screening do people with BHD need?
Lifelong kidney imaging, such as ultrasound, CT, or MRI on a schedule set by a doctor, is the most important screening because it catches kidney tumors early. Some people also have chest imaging to assess lung cysts. Relatives may be offered genetic testing.
References
- National Cancer Institute (NCI). Birt-Hogg-Dube Syndrome.
- Genetic and Rare Diseases Information Center (GARD). Birt-Hogg-Dube syndrome.
- MedlinePlus, U.S. National Library of Medicine. Birt-Hogg-Dube syndrome.
- National Organization for Rare Disorders (NORD).